The emulsion polymerization at moderate pressure of vinylidene fluoride using fluorinated surfactant and, as a free-radical initiator, diisopropyl peroxydicarbonate (hereinafter referred to as IPP) is taught in U.S. Pat. No. 3,475,396 dated Oct. 28, 1969. The same patent teaches that the amount of fluorinated surfactant necessary in the system can be reduced if a chain transfer agent, i.e. a water-soluble organic compound, is present in the reaction system. The process was further refined in U.S. Pat. No. 3,857,827 dated Dec. 31, 1974 wherein a particularly high molecular weight product was produced in a relatively fast reaction by a procedural modification wherein IPP initiator in a solution of acetone (the acetone acting both as a solvent for the IPP and as a chain transfer agent) was added incrementally (or continuously) to the reaction system simultaneously with and proportionately to the incremental (or continuous) addition of monomer. The present invention provides another procedural modification to attain a product of high molecular weight in a relatively fast reaction; additionally, the present process avoids the need to recover relatively large quantities of acetone to avoid environmental objections and the product of the present invention has improved stability toward discoloration upon aging, particularly in the presence of heat compared to the product of the '827 patent.